Mechanism for waxing cartons or the like



Nov. 4, 1941. A. D. BULLERJAHN 2,261,138

MECHANISM FOR WAXING CARTONS OR THE LIKE Filed July 10, 1959 4Sheets-Sheet 1 3g ZZZ/672223;

Nov. 4, 1941. A. D. BULLiERJAHN 2,251,138

MECHANISM FOR WAXING CARTONS OR THE LIKE Filed July 10, 1939 4Sheets-Sheet 3 Q6 77 $7 y Gama/ 0 Nov. 4, 1941. A. D. BULLERJAHNMECHANISM FOR WAXING CABTQNS OR THE LIKE Filed July 10, 1939 4Sheets-Sheet 4 Patented Nov. 4, 1941 UNITED STATE S PAT ENT OFFICEMECHANISM FOR WAXIN G OABTONS OR THE LIKE In the sealing-of perishablefood products or the like it is customary to apply to the filled cartona coating of paraifine or similar sealing substance inorder to preventthe ingress of moisture' and maintain the contents of the package in afresh and satisfactory condition.

In effectively sealing'a carton in this manner it is necessary that the.sealing'substance be evenly and continuously distributed over the entirev surface, including the sides and ends of the carton, and to secureuniform adhesion of the sealing substance to the carton surface, so thatno air will be anywhere entrapped in the form of bubbles or voids whichif present would tend to cause the coatingto flake away from the surfaceof the carton. It is also essential that no portion of the cartonsurface, during the application'of the coating, be contacted bymechanical means which would tend to obstruct the even application ofthe coating to the surface.

It has been the usual practice in the past to apply the coating to thecarton by dipping or immersion'in a bath of hot-parafiine, but thisrequires the employment of grippers or the like for holding the cartonduring the period of immersion and oftenresults in an unevendistribution of the coating-liquid or the presence of apertures in thecoating due to the entrapment of air or contact of the grippers employedto sustain the carton.

The object of the present invention is to overcome the diflicultiesabovenoted and to secure an even and uninterrupted coating throughoutthe .entire surface of the carton by the employment of jets of coatingliquid (parafline or the like) which in the liquid state are projectedagainst the exposed surfaces of a traveling carton in such a way as toeliminate the presence of grippers or the like in contact with thoseportions of the carton surface being subjected to the'coating'operation; and to effect an even distribution of the coatingliquid by moving the carton surface through the line of jets which notonly effect a uniform deposit of the coating but in effect perform thefunction of a mechanical wiper in evenly distributing the coating liquidin such a way as to prevent the entrapment of air with a resultantformation of bubbles or voids.

The present invention affords means for conveying the cartons in acontinuous procession and exposing each of the sides in turn to theimpingement of an underlying line of jets of coating liquid which isejected upwardly into contact with the downwardly presented surface ing,sweeps through the line of jets and becomes coated to the requireddegree, the carton being thereafter turned to present another face to alike line of jets, and so on until all of the side.

surfaces of the carton have been coatedin the manner stated, after whichprovision is made for coating the infolded ends of the carton prior toits final delivery.

Although for purposes of illustration mechanical means are providedfcrvthe coatingsequentially of the four sides of a rectangular carton,and for the intermittent rotation of the carton to present each of itsfiat sides in turn to a jet of parafiine or other coating liquid, thejet system here involved is equally applicable to the coating of .acylindrical carton, and the term carton, as employed in the presentspecification, is intended to cover any object, whether in the form of acontainer or the like, which is capable of being coated in the mannerpresently to be ing throughout every portion of the surface 1 described.The apparatus .is thus adapted for use in the application of paints,lacquers, or the like, or in other fields where it is desirable to applya uniform coating in liquid form and to effeet a smooth and evendistribution of the coat presented.

For the purpose of illustrating the principles involved, mechanism isprovided in the form of an endless carrier, which engages the ends ofthe cartons or other objects to be coated, and advances the same inprocessional relation above a tank which serves as a-reservoir for thecoating liquid (parafiine or the like) and which will usually be heatedto a moderate degree to afford the necessary fluidity to permit it to beejected in jet form, and which tank also serves as a basin into whichthe excess drippings fall during the progress of the cartons from end toend of the tank. Means are provided for recurrently tuming the cartonsduring their period of advance, so that each surfacein succession willbe presented to a line of jets to receive its coating, the spacing ofthe jets and the length and speed of the conveyor being properlycomputed to permit any excess coating liquid to drain from the car Iemploy mechanism of substantially the form shown in my Patent No.1,724,179, dated August of the carton wall, so that the latter, inadvanc- 13, 1929, which may be advantageously assoing units partiallybroken away to reveal the interior:

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a sectional elevation of one of the reservoirs for maintaininga head of coating liquid;

Fig. 6 is an enlarged sectional elevation taken I on the offset line 6-5of Fig. 3;

Fig. '7 is a sectional elevation of the mechanism for coating the endsof the cartons;

, Figs. 8 and 9 are details of the gripper mechanism for the ends of thecarton in associatio with fragments of the conveyor chains;

Fig. 10 is a detail of one of the conveyor chains with the gearmechanism for rotating the cartons;

Fig. 11 is an enlarged perspective view of one of the centering heads'for the rotating gripper mechanism; and

Fig. 12 is a detail of a modified form of rotating mechanism for usewith cylindrical cartons.

In the form shown, the mechanism occupies a position above an elongatedtank 20, which is adapted to contain a supply of liquid parafllne, fromwhich it is pumped into elevated reservoirs 2|, 22, 23, 24, 25, 26, bymeans of a pump 21 which supplies liquid to a main header pipe 28 havingbranch pipes 29 leading to the respective reservoirs. The branch pipesin each instance lead into the base of the associated reservoir. and thereservoirs themselves are all of similar construction, as illustratedwith respect to the reservoir 2| in Fig. 5, so that a description of onewill apply to all.

Each of the reservoirs 2|, 22, 23, 24, is provided with a tubular weir3| having in its upper end slots 32 which afford overflow apertures forthe maintenance of the proper head for the liquid. The weir is threadedonto the upper end of a pipe section 33 extending upwardly from thefloor of the reservoir and registering with a pipe 34 leading back tothe main supply tank. The tubular weir is adjustable within an upwardlyextending stack 36 closed by a cap 31, which permits access to theinterior for the purpose' of regulating the effective height of theweir.

Each reservoir discharges downwardly through a pipe 30 which connectsthrough a coupling 30' with the base of the associated jet unit 35,which is in the form of a shallow basin upturned around its margins 38,and which supports a jet plate 3! having rows of minute jet openings 40extending transversely of the main tank and interspersed by rows ofdrain. openings 4|. The individual jet openings are very close togetherand in continuous alignment, so that under the pressure afforded by thehead of liquid in the elevated reservoir they will permit the dischargeof continuous lines of jets J which in effect afford a continuous sheetor fountain of upwardly ejected coating liquid as illustrated in Fig. 4.In the present instance four lines of jets are provided interspersed bythree lines of drain openings, although obviously the number andarrangement of the jets and drain openings may be modified. The capacityof the drain openings 4| in relation to the discharge capacity of thejets is so restricted that a continuous surface of coating liquid willbe maintained between the jets, which supplements the coating action ofthe jets themselves.

The jet plate 39 is secured. to the basin by means of screws 42, or inany other suitable manner. Each iet unit basin is provided with a drainpipe 43 leading back to the main tank, and each unit is suitablysupported above the liquid in the tank and at a level such as to permitthe cartons or other objects requiring a coating to sweep above thesurface of the jet plate and in suiilciently close proximity thereto tocause impingement of the lines of jets against the surface thuspresented. Where rectangular cartons or the like are being coated it isnecessary to provide four jet units suitably spaced from one another .topermit cartons to be turned while traversiifi the gaps between the jetunits as in- T dicated in Fig. 2.

In orderto convey the cartons in processional relation and to expose thefour sides of the rectangular cartons successively to the jet coatingsprovided, endless conveyor chains 44 are employed which are carried uponsuitably driven sprocketsJS. The conveyor chains are located above themain tank and are composed of links 46 which at recurrent intervalsserve as mountings for brackets 41, each bracket, as shown, consistingof upstanding angle bars 48 rigidly secured to the associated link ofthe conveyor chain, and each bracket supports a rectangular open frame49 which carries a slidably mounted rod 50 provided at its inner endwith a clamping head 5]. Each clamping head on the right of Fig. 8 isnormally inwardly projected by a coil spring 52, and is provided onitsacting face with minute teeth 53 which engage the contiguous end of arectangular carton C, which is held between oppositely facing duplicateclamping heads, as shown in Fig, 8.

The right hand clamping head is provided with a collar 54 which isengaged by a bifurcated end 55 of a bell crank lever having at its freeend an upstanding finger 51 adapted to engage a fixed cam 58 suitablypositioned to retract the right hand gripping head to the dotted lineposition in order to permit the preliminary insertion of a carton, whichas shown may be carried by any suitable conveying mechanism 59 (Fig. 2)to the gripping position and there gripped by the release of the righthand gripping head preparatory to its advancement by the conjointmovements of the endless carrier chains.

In order to eflfect a turning of the carton at the required moment topresent another of its faces to the next coating jet, the left handclamping head (Fig. 8) has mounted thereon a spur gear 60 having a hubGI providedwith one or morelugs or ribs 62 adapted to register with thecross grooves 63 of a centering head 64 carried by the left hand frame49, the arrangement being such as to permit the slight yielding of theleft hand clamping head required to rotate the same, with the rib 62 incontact with the grooved centering head 64 and against the pressure of aspring 52*,

In order to effect rotation of the gear 60 at the proper interval, afixed toothed rack 65 is provided (Fig. 10), which occupies a positionin the line of travel of the spur gears 60, so that as each spur gearengages the rack it will be rotated through an arc of degrees, andthereafter accurately centered by the centering head sothattionoccasioned by the movement of the carton a new carton surface willbe presented for coating by the next set of jets in the series.

- It will be understood that the fixed rack mem- .bers 65, four innumber as shown, occupy positions intermediate the jet units 35, asshown in Fig. 2, so that after each application of the coating to one ofthe faces of the carton, the carton will be turned into position topresent the next face flatwise and in close proximity to the next jetunit, the spacing being duly computed with relation to the size of thecartons and the necessary clearance to be provided for turning them, andalso with relation to the period of time desired for permitting thefirst coating to harden somewhat before the carton is rotated into a newposition. These factors will be determined in have been coated in themanner described, the

surface through the upwardly projected jets performs a brushing functionin a much more advantageous manner than could be obtained by cartonswill be delivered successively into angle shaped carrier brackets 66mounted upon a second set of carrier chains 61 driven at a uniform speedwith the first set of chains and adapted to advance the cartons intoposition to have the ends successively sealedby sealing mechanism of thecharacter shown in my Patent No. 1,724,179 previouslysreferred to, andillustrated in Fig. 7.

This mechanism serves, by the overflow of the parafllne or other sealingmaterial, to apply a full coating to the folded and interlocked ends ofthe cartonby successive stages, one end being first presented forsealing and the other end'being subsequently sealed in the manner setforth in the patent above referred to. This completes the sealing ofallsix surfaces of a rectangular carton,'which is thereafter conveyed tothe point of delivery. It is not deemed necessary, however,

to describe this portion of the operation in detail since it is fullyset forth in my Patent No. 1,724,179.

Where cylindrical cartons or the like are to be coated, the modificationshown in Fig. 12 may be employed. In this instance, a basin 68 isemployed having a jet plate 69 provided with lines of apertures Iii forthe upward-projection of jet sheets of coating liquid against thecylindrical surface of a carton which in this instance will becontinuously rotated by the engagement of a pinion ll meshing with acontinuous rack I2, so that, as the cartons or other objects advance,the

of jets of coating until a complete rotation has been effected.

Other modifications adapted to cartons or similar objects of peculiar orunusual shape may be readily employed to meet special requirements andto insure that every portion of the side walls of the carton or otherobject will sweep through one or more coating jets in the mannerpreviously described.

It will be noted from the above description that during the coating ofthe side walls of the carton or other object, the same is supportedentirely from the ends and that'there is no mechanical contact with anyportion of the surface presented for coating, nor are mechanicalappliances provided for sweeping or brushing the coating liquid upon thesurface. At the same time the advancement of the carton itself throughthe upwardly ejected lines of jets effects a liquid brushing actlonwhich is highly advantageous in securing a uniform'adherence of thecoating liquid and in the use of mechanical means having frictionalcontact with the carton surface.

In the case of rectangular cartons also,.the surface being coated willlie in a plane closely adjacent to the jet plates, so that each surfacewill if desired be subjected to-the successive action of several rows ofjets, although it will be understood that the present inventioncontemplates the use of but a single row of jets as well as any multiplethereof. It will also be understood that although the mechanism isdesigned to successively apply a coating to each of the four sides of arectangular carton, the principles involved may be used in theapplication of a coating of sealing or other material to a planesurface, so that in the claims, unless otherwise indicated, it is notthe intention to limit the inven tion to a coating of surfaces of anyparticular shape or character, or to the use of sealing material asdistinguished from paints, lacquers, or other coating material adaptedto be applied to surfaces in general.

Furthermore, the intensity of the impingement of the liquid jets uponthe surface presented, and the intensity of the brushing effect producedby travel through the impinging jets, can be easily regulated byincreasing or diminishing the pressure head of the coating liquid, or byother equiv-- alent means for regulating such pressure, so that fullprovision can be made for variations in the quality or thickness of thecoating within wide limits and without the use of mechanical devices fordirectly'assisting in the distribution of the coating.

1 claim:

1. In a machine for coating the angularly disposed surfaces of anobject, the combination of a plurality of jet supplying units spacedfrom one another and each apertured to upwardly discharge an elongatedjet in the form of a sheet to eilect a brushing action against thesurface of the object being coated, conveyor means adapted to engage theend of the object to be coated and convey the same successively aboveand through said jets and means associated with said conveyor forintermittently rotating said object while in progress between said jetsto successively bring the underlying surfaces of said object intocontact with successive jets of said series, and means for supplying acoating liquid to each of said jet supplying units under pressure.

2. In a machine for coating rectangular objects, the combination of amain tank, a plurality of jet supplying units located verticallyadjacent to said tank and spaced from'one another and each provided withclosely spaced apertures adapted in unison to upwardly eject jets whichin combined relation present the form of a sheet to effect a brushingaction against thesurface of the object being coated, meanscommunicating with each of said jet supplying units for sunplying acoating liquid thereto, an endless conveyor provided at recurrentintervals with means for gripping the ends of said rectangular objectsand adapted to carry the same forwardly above the jets in successionwhile downwardly presented into proximity with said jet supplying units,and

means-for intermittently turning saidobjects preventing the entrapmentof air, since the fric- 7 relation with successive jet supplying units.

3. In a machine for coating rectangular objects, the combination 01 amain tank, a plurality of jet supplying units located verticallyadjacent to said tank and each provided with closely spaced aperturesadapted in unison to upwardly eject jets which in combined relationpresent the form of a sheet to effect a brushing acproximate relationwith successive jet supplying units, and weir means in said reservoirmeans adapted to permit regulation in the intensity of the pressurehead.

4. In a machine for coating rectangular objects, the combination of amain tank, a pluralityof jet supplying units located above said tank andeach aper-tured to upwardly elect a sheet of liquid transversely acrossthe line of movement of the rectangular objects, means communicatingwith each of said jet supplying units for supplying a coating liquidthereto, a pair of spaced endless conveyors provided at recurrentinterbring each of said surfaces in succession into 20 vals withrotatable clamping heads opposed to the heads on the companion conveyorand adapted in unison to clamp the ends of rectangular objectstherebetween and adapted to carry the same forwardly above the jetsupplying units to bring each of the side surfaces in succession whiledownwardly presented into proximity with one of said jet supplyingunits, and means for intermittently turning said clamping heads duringthe interval of passage of the rectangular objects i'rom one jetsupplying unit to the next to bring each of said surfaces in successioninto proximate relation with each successive jet supplyin unit. 7

ADOLPH D. BULLERJAHN.

